Language delay is pervasive among preschool children. Early detection and preventative intervention is crucial since the consequences of language delay can be cumulative, yet research shows that language intervention is not usually provided. We propose to develop a microcomputer-based system that can be used for language assessment and intervention over the Internet. We envision a system that includes (a) an on-line assessment based on the MacArthur Communicative Development Inventory that can collect and interpret parent report data and report results back to parents. and (b) an on-line intervention system designed to facilitate language - development in older infants and late.talking toddlers from l 2 to 36 months of age. The curricular design of the system will be based on contemporary- linguistic research. On-line delivery of the intervention curriculum will be individualized and controlled by an artificial intelligence system that tracks ongoing performance. Our Phase goal is to test the feasibility and technical merit of our plans. A prototype intervention module for early vocabulary development will be placed on- line, and 14 to 20 month old children who are late talkers will be given an opportunity to use the module at home with their parents. PROPOSED COMMERCIAL APPLICATIONS: Speech-language pathologists, teachers, and parents recognize the importance of early intervention when a child's language status is impaired, and such intervention is mandated by Federal law. We anticipate that an Internet-based intervention system to prevent language disorders and facilitate language development will be a commercial success and will fulfill an unmet need for individualized services.